Malaria is a febrile illness caused by several protozoan species in the genus Plasmodium. The parasite is transmitted to humans by bites from infected Anopheles genus mosquitoes. The risk of malarial infection is highest in the tropical and sub-tropical regions of the world. Although local transmission of malaria frequently occurred in Minnesota over 100 years ago, all of the cases reported in Minnesota residents since that time likely have been imported infections acquired abroad.
In 2011, 47 malaria cases (0.9 per 100,000 population) were reported in Minnesota residents, slightly above the 2000 to 2011 annual median of 40 cases (range, 29 to 50). Thirtytwo (68%) cases were identified with P. falciparum, 7 (15%) with P. vivax, 3 (6%) with P. ovale, 2 (4%) with P. malariae, and 3 (6%) with mixed Plasmodium species infections. The median age of cases was 33 years (range, 1 to 75 years). Of 35 cases of known race, 24 (69%) were black, 8 (23%) were white, and 3 (9%) were Asian. Eighty-three percent of cases resided in the metropolitan area, including 27 (57%) in Hennepin or Ramsey Counties. Of the 31 cases with known country of birth, 11 (35%) were born in the United States. Thirty-eight (81%) cases in 2011 likely acquired malaria in Africa. Six cases were likely acquired in Asia, 1 in Oceana, 1 in Central America, and 1 in the Caribbean. Twenty-three countries were considered possible exposure locations for malarial infections, including Liberia (10), Nigeria (7), and Ghana (5).
- For up to date information see>> Reporting Malaria (Plasmodium spp.)
- Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2011